Claude Opus 4.5 vs DeepSeek-V4.1-Flash
Wins 1 of 8 areas
Facts
Wins 7 of 8 areas
Coding · Agents · Reasoning · Images and charts · Math · Long documents · Following instructions
DeepSeek-V4.1-Flash is the stronger all-rounder.Claude Opus 4.5 is better at facts.
Scores updated · 32 tests both models report · How we compare
Where each one wins
Tests won in each of the eight areas we test. Each piece is one test, so a longer bar means more evidence; grey means the two scored within a point of each other.
- ReasoningHard problems that need careful thinking05DeepSeek-V4.1-Flash5 of 5 tests
- CodingWriting and fixing software03DeepSeek-V4.1-Flash3 of 4 tests · 1 tie
- MathCompetition and research-level math03DeepSeek-V4.1-Flash3 of 3 tests
- Images and chartsUnderstanding pictures, charts and video02DeepSeek-V4.1-Flash2 of 2 tests
- AgentsCarrying out multi-step tasks on its own01DeepSeek-V4.1-Flash1 of 1 test
- Long documentsFinding answers in very long texts01DeepSeek-V4.1-Flash1 of 1 test
- Following instructionsDoing exactly what it is asked01DeepSeek-V4.1-Flash1 of 1 test
- FactsGetting facts right instead of making them up20Claude Opus 4.52 of 3 tests · 1 tie
Agents, long documents and following instructions rest on a single test each.
What it costs
Prices per million tokens, roughly 750,000 words. The bars show the cost of a million tokens read plus a million written.
DeepSeek-V4.1-Flash costs 95% less for the same work.
The biggest differences
The tests each model wins by the widest margin, up to three each. Scores are out of 100.
Where DeepSeek-V4.1-Flash pulls ahead
- Extremely hard research-level math problemsFrontierMath Tier 4+41.4points ahead
- Abstract visual puzzles that people can solveARC-AGI-2+40.5points ahead
- Fixes real GitHub issues, working as an agentLiveBench · Agentic Coding+37.6points ahead
Where Claude Opus 4.5 pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+35.5points ahead
- Short factual questions, answered correctlySimpleQA Verified+2.8points ahead
Every test, side by side
All 32 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingDeepSeek-V4.1-Flash
- LiveBench · Agentic CodingDeepSeek-V4.1-Flash by 37.639.777.3+37.6
- LMArena · WebDevDeepSeek-V4.1-Flash by 150 rating points14691619+150 rating
- SciCodeDeepSeek-V4.1-Flash by 2.449.551.9+2.4
- LiveBench · Codingtie79.780tie
ReasoningDeepSeek-V4.1-Flash
- ARC-AGI-2DeepSeek-V4.1-Flash by 40.537.678.1+40.5
- CritPtDeepSeek-V4.1-Flash by 9.74.614.3+9.7
- Humanity's Last ExamDeepSeek-V4.1-Flash by 9.130.139.2+9.1
- LiveBench · ReasoningDeepSeek-V4.1-Flash by 6.680.186.7+6.6
- GPQA DiamondDeepSeek-V4.1-Flash by 4.386.690.9+4.3
FactsClaude Opus 4.5
- AA-Omniscience · Non-hallucinationClaude Opus 4.5 by 35.5393.5+35.5
- SimpleQA VerifiedClaude Opus 4.5 by 2.845.742.9+2.8
- AA-Omniscience · Accuracytie46.646.4tie
Images and chartsDeepSeek-V4.1-Flash
- MMMU-ProDeepSeek-V4.1-Flash by 37477+3
- CharXiv (RQ)DeepSeek-V4.1-Flash by 1.867.269+1.8
MathDeepSeek-V4.1-Flash
- FrontierMath Tier 4DeepSeek-V4.1-Flash by 41.44.946.3+41.4
- FrontierMath Tiers 1-3 (v2)DeepSeek-V4.1-Flash by 36.834.471.2+36.8
- LiveBench · MathematicsDeepSeek-V4.1-Flash by 2.990.493.3+2.9
Long documentsDeepSeek-V4.1-Flash
- AA-LCRDeepSeek-V4.1-Flash by 6.777.384+6.7
Following instructionsDeepSeek-V4.1-Flash
- LiveBench · Instruction FollowingDeepSeek-V4.1-Flash by 7.462.570+7.4
Other results12 tests, not counted
Tests outside the eight areas. They are not counted above: several are summary scores built from other tests, or the same test under another name.
- ZeroBenchDeepSeek-V4.1-Flash by 46349+46
- CyberGymDeepSeek-V4.1-Flash by 37.550.688.1+37.5
- NL2RepoDeepSeek-V4.1-Flash by 20.843.264+20.8
- HLE (with tools)DeepSeek-V4.1-Flash by 20.543.463.9+20.5
- AA-OmniscienceClaude Opus 4.5 by 19.314-5.3+19.3
- ARC-AGI-1DeepSeek-V4.1-Flash by 11.58293.5+11.5
- AA IntelligenceDeepSeek-V4.1-Flash by 10.429.139.5+10.4
- vectara_factual_consistencyDeepSeek-V4.1-Flash by 6.789.195.8+6.7
- livebench_data_analysisDeepSeek-V4.1-Flash by 4.974.479.3+4.9
- vectara_answer_rateDeepSeek-V4.1-Flash by 1.298.799.9+1.2
- vectara_avg_summary_lengthtie114.5108.2tie
- livebench_languagetie81.381.2tie
Questions people ask
Which is better, Claude Opus 4.5 or DeepSeek-V4.1-Flash?
DeepSeek-V4.1-Flash wins seven of the eight areas we test: coding, agents, reasoning, images and charts, math, long documents and following instructions. Claude Opus 4.5 wins facts.
Which is better for coding?
DeepSeek-V4.1-Flash. It wins 3 of the 4 coding tests both models report; Claude Opus 4.5 wins none, and 1 is a tie.
Which is cheaper?
Claude Opus 4.5 costs $5.00 per million input tokens and $25.00 per million output tokens; DeepSeek-V4.1-Flash costs $0.30 and $1.20. That makes DeepSeek-V4.1-Flash about 95% cheaper for the same work.
How do you compare the two?
We use the 32 benchmark tests both models have published scores on. The verdict counts the 20 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 12 are listed but not counted, because several are summary scores or repeat a test. Each score is the one shown on the model's own page.